Bug 200552

Summary: kernel panic on cat /proc/net/ip_conntrack_expect
Product: Red Hat Enterprise Linux 4 Reporter: Mark Tinberg <mtinberg>
Component: kernelAssignee: Neil Horman <nhorman>
Status: CLOSED INSUFFICIENT_DATA QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.0CC: davem, jbaron, tgraf
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Target Release: ---   
Hardware: i386   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2007-08-08 18:47:19 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
iptables lokkit config none

Description Mark Tinberg 2006-07-28 16:46:22 UTC
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Description of problem:
Unexpected kernel panic when I tried looking at contrack data using the command 

 cat /proc/net/ip_conntrack_expect

Unfortunately I needed this system up immediately and did not write out the kerenl panic data although it 
did seem to be related to accessessing this file in /proc.

Version-Release number of selected component (if applicable):
kernel-smp-2.6.9-34.0.1.EL

How reproducible:
Didn't try


Steps to Reproduce:
1.
2.
3.

Actual Results:


Expected Results:


Additional info:
System is a Dell PE 2850 with a single 2.8GHz Xeon with HT enabled. and 1GB RAM

Comment 2 Neil Horman 2006-07-31 13:13:39 UTC
Its not solely related to accessing the proc file, as I'm able to read the file
here without reproducing the problem.  Its most likely, given that this file is
protected by two rwlocks, that this is a race generated by trying to read the
file while receiving packets with the filter configured.  Can you provide your
iptables  configuration?  Also, would you be able to reproduce the problem while
running a custom kernel with CONFIG_NETFILTER_DEBUG enabled?

Comment 3 Mark Tinberg 2006-07-31 17:10:02 UTC
Created attachment 133333 [details]
iptables lokkit config

contents of /etc/sysconfig/iptables on affected machine

Comment 4 Mark Tinberg 2006-07-31 17:17:22 UTC
Unfortunately I cannot reproduce this on the referenced machine as it is a production server.

Comment 5 Neil Horman 2006-07-31 17:34:41 UTC
Thank you for the iptables config.  If you can in any way manage to reproduce
that oops, it would be helpful to me.  I'm going to try to reproduce here, but
unless I can, there likely won't be much I can do for this bug.



Comment 7 Neil Horman 2006-10-23 19:45:57 UTC
Mark-
     I'm not sure if you are able, but if you have a test machine that you can
reproduce this on, could you please test against the RHEL5 beta release?  That
would help me narrow down if the above patches apply to this bug you are seeing,
as I am still unable to reproduce.